sonic-visualiser (audio file visualiser)

Sonic Visualiser is an application for viewing and analysing the
contents of music audio files. The aim of Sonic Visualiser is to be
the first program you reach for when want to study a musical recording
rather than simply listen to it.

Optional dependency, detected at build time:

portaudio - allows sonic-visualiser to run without a JACK or pulseaudio
server (using plain ALSA).

Note: PulseAudio seems to work but hasn't been thoroughly tested. If
you have problems with the other audio I/O backends, try JACK. See File
-> Preferences -> Audio I/O.

[*] When built with jack, this package uses POSIX filesystem
capabilities to execute with elevated privileges (required for realtime
audio processing). This may be considered a security/stability
risk. Please read http://www.slackbuilds.org/caps/ for more
information. To disable capabilities, pass SETCAP=no to the script, or
build without JACK.